Honing stone and method of



April 20, 1954 w. H. HARRIS, JR

HONING STONE AND METHOD OF MANUFACTURE 2 Sheets-Sheet 1 Filed Feb. 13,1950 I INVENTOR. #41124? Harris, J:

April 20, 1954 w. H. HARRIS, JR 2,675,654

HONING STONE AND METHOD OF MANUFACTURE Filed Feb. 13, 1950 2Sheets-Sheet 2 INVENTOR. Mk??? /'9, #4/7 25, 7;.

BY I

M 24 Mix Patented Apr. 20, 1954 HONING STONE AND METHOD OF MANUFACTUREWilliam H. Harris, Jr., Detroit, Mich., assignor to Micromatic HoneCorporation,

Detroit,

Mich., a corporation of Michigan Application February 13, 1950, SerialNo. 144,008

11 Claims. (Cl. 51-204) This invention relates generally to honing toolsand more particularly to a honing element and a method of manufacturingthe same.

It is an object of this invention to provide a honing element in whichthe honing stone or abrasive element is mounted and supported in anonabrasive backing member, so that as the stone wears the encasingportion of the backing member will likewise wear, whereby the stone maybe used until it is completely worn away, rather than replaced when onlypartially worn, such as is the case when metal backing members, or thelike, are used to support the stone.

It is a still further object of this invention to provide a honingelement of the aforementioned type, which may be easily and positivelypositioned in a grinding tool, and which is relatively inexpensive tomanufacture and econimical to use.

It is a still further object of this invention to provide a honingelement of the aforementioned type, which is rugged in construction anddurable in use, and in which the nonabrasive backing member isreinforced so as to reduce any danger of breakage or deformation of theelement.

It is a still further object of this invention to provide a novel methodof manufacturing a honing element of the aforementioned type, whichmethod is extremely simple and inexpensive.

It is a still further object of this invention to provide a honingelement of the aforementioned type, in which the backing member is madeof a moldable material, such as plastic, so that the entire element canbe molded together in one simple operation.

It is a still further object of this invention to provide a method ofmanufacturing honing elements, which permits a pair of honing elementsto be simultaneously formed in a single mold and then severed orseparated to produce a pair of either like or dissimilar honingelements.

These and other objects of this invention will become apparent from thefollowing detailed description, taken in conjunction with theaccompanying drawings, in which:

Figure 1 is a side elevational view, partially broken away in. section,of a portion of a grinding tool having the honing elements of thisinvention connected therewith;

Fig. 2 is a sectional view of the structure illustrated in Fig. 1, takenalong the line 22 thereof;

Fig. 3 is a perspective view of a honing element of this invention;

Fig. -4 is an exploded perspective view of a. pair of honing stones anda honing element reinforcing member prior to the assembly of theseelements into a finished molded honing element;

Fig. 5 is a side elevational View of a portion of a mold having a pairof honing stones and a reinforcing member positioned therein;

Fig. 6 is a sectional view of the structure illustrated in Fig. 5, takenalong the line 66 thereof;

Fig. '7 is a sectional View similar to Fig. 6, with the moldablematerial in the mold;

Fig. 8 is a perspective view of the article formed. in the mold of Figs.5 through 7, prior to the separation of the article into two honingelements; and

Fig. 9 is a view similar to Fig. 5, illustrating a further embodiment ofthe honing element of this invention, being formed in a mold.

Referring now to the drawings and more particularly to Fig. 3, a honingelement H is illustrated, which includes a honing stone or abrasiveelement l3 and a non'abrasive backing member IS. The honing stone l3 hasall but its working face I! encased by the backing member l5, and theopposite sides of the backing member l5 have integral rectangularlyshaped tabs or projections l9 formed thereon. In the particularembodiment illustrated, two such projections I!) are provided on eachside of the backing member 15, and the projections extend rearwardlyfrom the stone working face I! to the back face of the backing memberl5. Three longitudinally spaced grooves 2! are formed in each side faceor wall of the backing member i 5, and these grooves extend rearwardlyfrom the working face of the honing stone I 3- to the back face of thebacking member I5, for reasons which will hereinafter appear.

The top and bottom end walls of the backing member l5, rearwardly of theback face of the honing stone !3, are notched at 22, for reasons whichwill hereinafter appear. Imbedded in the backing member l5 are a pair ofreinforcing members 23 and 25. The reinforcing member 23 is of anoppositely zigzagged shape, or has expanded or laterally offset portions21, so that it is of substantially the same width as the honing stoneIS. The reinforcing member 23 extends substantially the full length ofthe honing stone 1? and the front edge thereof engages the back face ofthe honing stone l3, while the back edge thereof terminates at the backface of the backing member I5. The reinforcing member 25 is in the formof a flat plate and has one side face thereof engaging one side of therein forcingmember 23. Member 25 is shorter than member 23, so that itabuts only an intermediate portion of member 23.

Two honing elements, such as illustrated in Fig. 3, are simultaneouslyformed in a mold 29, such as illustrated in Figs. through '7. The mold29 is shown as being formed of two halves 3| and 33, which, whenassembled, form a mold cavity 35. In forming the finished honingelement, two honing stones l3 are placed in the mold cavity 35 and arespaced apart by the reinforcing elements 23 and 25, which, when insertedin the mold cavity, retain the opposed working faces of the honing stonein engagement with the end walls of the mold cavity. The opposite sidewalls of the cavity 35 are formed with three longitudinally spaced,laterally extending ribs 31, which engage the opposite side faces of thehoning stones so as to maintain them in a spaced relation with respectto the side walls of the cavity. The side walls of the mold cavity 35are also recessed at 39, at longitudinally spaced points, for reasonswhich will hereinafter appear. The cavity mold is then filled withmoldable material, such as phenyl and vinyl resins and the like, whichis of a nonabrasive character. A suitable molding operation is thenperformed so that the plastic or nonabrasive material forms a backingmember encasing the reinforcing members and all but the working faces ofthe honing stones It. The molded article is then removed from the mold,and is in the form illustrated in Fig. 8. By cutting the articleillustrated in Fig. 8 along substantially the longitudinal center line ii, two

honing elements, of the type illustrated in Fig. 3, are provided. Thenotches 22 are ground or cut in the top and bottom edges of the honingelements, either before or after the severing operation, so as toprovide the finished elements.

The two honing elements formed from the one molded article illustratedin Figs. 5 through 8 are exactly similar. However, it is possible, withthe method and construction of this invention, to form dissimilar honingelements such as illustrated in Fig. 9, wherein one honing stone I3 isof the same length as that previously illustrated, while the otherhoning stone I3" is of a shorter length. With this arrangement, thehoning stone i3 is positioned with respect to the reinforcing member 23,by lancing tabs 43 from one side edge of the reinforcing member 23,which tabs will retain the honing stone [3 in the proper relation to thereinforcing member during the molding operation. When the mold cavity isfilled with moldable material, the space above and below stone [3 willbe filled with the material, which will wear at the same rate as thestone and will not interfere with the honing operation. The remainder ofthe method of forming the honing elements is the same as previouslydescribed, and when the molded article is longitudinally separated orout two dissimilar honing elements are provided, one with a long stoneand the other with a short stone.

In order to use the elements H in a honing operation, they are mountedin a suitable grinding or honing tool M. The tool illustrated in thedrawing comprises three longitudinally spaced spiders 45 which arerecessed at 41, at circumferentially spaced points to receive aplurality of the honing elements I Cam shoes 49 are disposed in theslots l! inwardly of the honing elements H and the cam shoes areengageable in a conventional manner by cam elements 5| so that thehoning elements can be moved radially inwardly or outwardly relative tothe spiders. Garter springs 53 extend around the tool, at the upper andlower ends of the honing elements, and. are positioned in the honingelement notches 23 so as to resiliently hold the honing elements inposition in the spiders. The projections or tabs I9 of the honingelements fit into recesses in the spiders 45 so as to prevent relativeaxial movement: between the honing elements and the spiders. A pluralityof wiper elements 55, which may be made of wood, plastic, or some othersuitable nonabrasive material, are mounted in recesses in the spiders,at circumferentially spaced points, for the usual purpose.

It will thus be seen that the nonabrasive backing member I5 of eachhoning element can wear with the honing stone I3 and the honing elementsneed not be replaced until the entire honing stone is completely worn.Thus, the full benefit of the honing stone is achieved, and the honingelement need not be repaired or replaced before the stone is completelyworn, such as. is generally the case with most honing elementconstruction, where a nonabrasive backing member is not employed.

Furthermore, it will be appreciated that the projections or tabs on thehoning element provide a simple means of positioning or anchoring thehoning element in the honing tool, while the grooves or notches 22provide a simple means for engagement with the garter springs whichresiliently retain the honing elements in their proper position. Stillfurther, the ribs 31 of the molds, which form the grooves 2! in thebacking members, positively position the honing elements or stones inthe mold and insure uniform molding of the material about the honingstone and reinforcing member. Also, as the greatest forces exerted onthe honing element, during a honing operation, are in a radially inwarddirection, the zigzag construction of the reinforcing member 23 givesthe necessary added strength and rigidity to the backing member l5 toprevent the same from materially deflecting, breaking or becomingdamaged. Also, the reinforcing plate 25 aids in preventing deflection orbending of the entire honing element in the opposite plane. Thus, adurable, rigid, inexpensive honing element is provided, which is formedin one simple molding operation, and which is extremely inexpensive tomanufacture and use.

What is claimed is:

1. A honing element for a grinding tool, including a honing stone unit,a backing and supporting member of molded plastic materialencasing saidstone on all but its Working face, and a reinforcing member imbedded insaid molded material and having one edge abutting against the adjacentface of said stone.

2. A honing element for a grinding tool, including a honing stone, anonabrasive backing and supporting member encasing all but one face ofsaid stone an edgewise disposed reinforcing member of sheet metalimbedded in said backing member behind said stone and extending in onedirection from the back encased face of said stone to the back face ofsaid backing member and substantially the entire length of said stone.

3. A honing element for a grinding tool, including a honing stone, aplastic backing and supporting member encasing all portions except theworking face of said stone, a reinforcing member imbedded in saidbacking member behindsaid stone, said reinforcing member having portionslaterally expanded or offset so that said reinforcing member extendssubstantially the width of said stone.

4. A honing element for a grinding tool, including a honing stone, aplastic backing and supporting member encasing all portions except theworking face of said stone, an oppositely zigzagged reinforcing sheetmetal element imbedded in said backing member behind said stone andextending substantially the width and length of said stone, one edge ofsaid reinforcing element substantially engaging the back face of saidstone, a second plate-like reinforcing element imbedded in said backingmember behind said stone and adjacent to said first reinforcing element.

5. The method of making a honing element for a grinding tool, includingthe steps of positioning a reinforcing member between a pair of honingstones, of encasing said reinforcing member and all but the opposedfaces of said honing stones with a plastic material, and oflongitudinally cutting the article so formed so as to provide two honingelements.

6. The method of forming a honing element for a grinding tool, includingthe steps of positioning a pair of honing stones in a mold, positioningreinforcing means between said stones, of molding a, material around andin engagement with said reinforcing member and stones so as to encasesaid reinforcing means and all but one face of each of said stones, ofremoving the articles so formed from the mold, and of longitudinallysevering the article so as to form two honing elements.

7. The method of forming a honing element for a grinding tool, includingthe steps of positioning a pair of honing stones in the cavity of amold, of separating the stones by positioning lation to the wall of saidmold cavity, of molding material around said stones and reinforcingmember so as to encase said reinforcing means and all but one face ofeach of said stones and produce a molded article, of removing saidarticle from said mold, and of severing said article along itssubstantially longitudinal center line so as to provide two like honingelements.

8. An article of manufacture, including a pair of laterally spaced,longitudinally extending abrasive elements, one of which is of asubstantially greater length than the other, a reinforcing memberdisposed between said abrasive elements for spacing the elements, meanson one edge of said reinforcing member engaging the opposite end facesof the shorter of said abrasive elements for positioning the same withrespect thereto, and a plastic backing and supporting member encasingall portions except the faces opposite to the adjacent faces of saidabrasive elements and filling the space therebetween.

9. A method of simultaneously forming a pair of dissimilar honingelements for a grinding tool, including the steps of separating a pairof honing stones of different lengths with a reinforcing element ofsubstantially the length of the longer abrasive element, of positioningthe shorter stone relative to the longer stone by said reinforcingmember, of encasing all but the faces opposite to the adjacent faces ofeach of said stones with a plastic material, and of severing the articleso formed along its substantially longitudinal center line so as toprovide two dissimilar honing elements.

10. A honing element for a grinding tool, including an abrasive element,a nonabrasive backing and supporting member of a substantially greaterlength than said abrasive element and encasing all portions except theone face of said abrasive element, a reinforcing member imbedded in saidbacking member behind said abrasive element and being of a substantiallygreater length than said abrasive element, and means on said reinforcingmember engaging the ends of said abrasive element so as to retain thesame in a predetermined position with respect to said reinforcingmember.

11. A honing element for a grinding tool, including a honing stone ofsubstantial length relative to its width and thickness, a unit backingand supporting case of molded plastic material encompassing said stoneon all but its working face and being bonded thereto, said case at theends and two opposite sides being comparatively thin so as to wear awayas the abrasive material on the working face breaks down during thehoning operation, the material on the side opposite to the working facebeing substantially thicker as compared with the thin material at theside and end walls, and a pair of rectangular-shaped tabs projectingfrom said opposite Side walls, said tabs being spaced from each otherand the ends of the element and aligned on opposite sides thereof.

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